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Understanding the dynamics of superparamagnetic particles under the influence of high field gradient arrays

Understanding the dynamics of superparamagnetic particles under the influence of high field gradient arrays
Understanding the dynamics of superparamagnetic particles under the influence of high field gradient arrays
The aim of this study was to characterize the behaviour of superparamagnetic particles in magnetic drug targeting (MDT) schemes. A 3-dimensional mathematical model was developed, based on the analytical derivation of the trajectory of a magnetized particle suspended inside a fluid channel carrying laminar flow and in the vicinity of an external source of magnetic force. Semianalytical expressions to quantify the proportion of captured particles, and their relative accumulation (concentration) as a function of distance along the wall of the channel were also derived. These were expressed in terms of a non-dimensional ratio of the relevant physical and physiological parameters corresponding to a given MDT protocol.

The ability of the analytical model to assess magnetic targeting schemes was tested against numerical simulations of particle trajectories. The semi-analytical expressions were found to provide good first-order approximations for the performance of MDT systems in which the magnetic force is relatively constant over a large spatial range. The numerical model was then used to test the suitability of a range of different designs of permanent magnet assemblies for MDT. The results indicated that magnetic arrays that emit a strong magnetic force that varies rapidly over a confined spatial range are the most suitable for concentrating magnetic particles in a localized region. By comparison, commonly used magnet geometries such as button magnets and linear Halbach arrays result in distributions of accumulated particles that are less efficient for delivery. The trajectories predicted by the numerical model were verified experimentally by acoustically focusing magnetic microbeads flowing in a glass capillary channel, and optically tracking their path past a high field gradient Halbach array.
Magnetic drug targeting, halbach array, magnetic nanoparticle, acousticradiation pressure, particle trajectory, targeted drug delivery
2333-2360
Barnsley, Lester C.
da7b9324-6305-4b35-8e4e-0f4a6410aa25
Carugo, Dario
0a4be6cd-e309-4ed8-a620-20256ce01179
Aron, Miles
4d9c7843-bbe5-4a5d-975f-ea58a09fc621
Stride, Eleanor
c0143e95-81fa-47c8-b9bc-5b4fc319bba6
Barnsley, Lester C.
da7b9324-6305-4b35-8e4e-0f4a6410aa25
Carugo, Dario
0a4be6cd-e309-4ed8-a620-20256ce01179
Aron, Miles
4d9c7843-bbe5-4a5d-975f-ea58a09fc621
Stride, Eleanor
c0143e95-81fa-47c8-b9bc-5b4fc319bba6

Barnsley, Lester C., Carugo, Dario, Aron, Miles and Stride, Eleanor (2017) Understanding the dynamics of superparamagnetic particles under the influence of high field gradient arrays. Physics in Medicine and Biology, 62 (6), 2333-2360. (doi:10.1088/1361-6560/aa5d46).

Record type: Article

Abstract

The aim of this study was to characterize the behaviour of superparamagnetic particles in magnetic drug targeting (MDT) schemes. A 3-dimensional mathematical model was developed, based on the analytical derivation of the trajectory of a magnetized particle suspended inside a fluid channel carrying laminar flow and in the vicinity of an external source of magnetic force. Semianalytical expressions to quantify the proportion of captured particles, and their relative accumulation (concentration) as a function of distance along the wall of the channel were also derived. These were expressed in terms of a non-dimensional ratio of the relevant physical and physiological parameters corresponding to a given MDT protocol.

The ability of the analytical model to assess magnetic targeting schemes was tested against numerical simulations of particle trajectories. The semi-analytical expressions were found to provide good first-order approximations for the performance of MDT systems in which the magnetic force is relatively constant over a large spatial range. The numerical model was then used to test the suitability of a range of different designs of permanent magnet assemblies for MDT. The results indicated that magnetic arrays that emit a strong magnetic force that varies rapidly over a confined spatial range are the most suitable for concentrating magnetic particles in a localized region. By comparison, commonly used magnet geometries such as button magnets and linear Halbach arrays result in distributions of accumulated particles that are less efficient for delivery. The trajectories predicted by the numerical model were verified experimentally by acoustically focusing magnetic microbeads flowing in a glass capillary channel, and optically tracking their path past a high field gradient Halbach array.

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More information

Accepted/In Press date: 23 January 2017
e-pub ahead of print date: 24 February 2017
Published date: 21 March 2017
Keywords: Magnetic drug targeting, halbach array, magnetic nanoparticle, acousticradiation pressure, particle trajectory, targeted drug delivery
Organisations: Bioengineering Group, Mechatronics

Identifiers

Local EPrints ID: 405180
URI: https://eprints.soton.ac.uk/id/eprint/405180
PURE UUID: a051411e-0357-4595-9a2c-c952efa85638

Catalogue record

Date deposited: 30 Jan 2017 10:10
Last modified: 14 Aug 2019 17:55

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